Rotax four stroke aircraft engines have proven themselves as reliable pieces of machinery. They can be bought as experimental (UL) or certified (A and F) engine and there are four main models (injected too) to date. The original engine is the 80 hp 912, from which the 100 hp 912S was developed and Rotax also has a 115 hp turbocharged 914 engine. In 2015 Rotax announced the 135 hp fuel injected turbocharged 915iS.
Service instruction SI-27-1997 decribes the proper procedure for checking the oil level in a Rotax 912 or 914 engine by removing the oil tank cap, rotating the propeller in the normal direction until air is forced back into the oil tank. Do this at pre-flight and at each maintenance check.
Always keep the oil level between the minimum and maximum level marks on the dipstick. On longer flights take some extra oil with you and keep the level at maximum.
SI-27-1997, Oil level check
Excerpt from the document:
Additional and detailed information regarding the checking of the oil level on ROTAX® engines of type 912 and 914 are considered to be necessary.
Incorrect oil level readings are being caused by incorrect oil level check procedures. 1.4) Subject Oil level check. 1.5) Compliance At the pre-flight check or the next maintenance event.
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